Electric machine



Feb. 17, 1931. 0.1. BLATHY 1'.19a,4s.4

ELECTRIC MACHINE Filed Feb. 11, 1928 3 Sheets-Sheet 1 an a .9 12162213,

a z F fizzy;

Feb. 17, 1931. o T. BLATHY 1,793,434

ELECTRIC MACHINE Filed Feb. 11, 1928 5 Sheets-Sheet 2 I 72/2) an to r 0 Zia Bias Blaihy,

Ivy 37M 1 02: 25

Feb. 17, 1931. o, BLATHY 1,793,434

ELECTRIC MACHINE Filed Feb. 11. 1928 3 Sheets-Sheet 3 Inventor.-

e 0110 Tiiws 1316311 Patented Feb. 17, 1931 EINITED STATES PATENT OFFICE OTTO TITUS BLATHY, F BUDAPEST, HUNGARY ELECTRIC MACHINE Application filed February 11, 1928, Serial No. 253,697, and in Hungary and Germany February 23, 1927.

'lhis invention rel-ates to cooling arrangcthe thickness of the cooling elements in the men-ts for electrical machines wherein both axial direction is substantially increased and liquid and air are employed as cooling agents. secondly the manufacture of such elements The primary objectof the invention is to attended by diiliculties.

provide for the stator a liquid-cooling ar- The best solution of the problem is to ar- 5 rangcment which constitutes at the same range the air ducts between the cooling eletime eflicient cooling means for the air coolments and; the stator iron, to be cooled and ing the rotor. Another object of the invento provide for said stator iron being in contion is to enable the cooling air to complete ductive contact with said elements.

its circulation within the machine. A fur- Several examples of cooling devices emther object of the invention is to make the bodying the present invention are illustratedv amount or cooling air conducted in a closed in the accompanying drawing in which: circuit through the machine as small as posg- 1 i5 EL diagrammatic Cross SQCtiOn Of a sible, thereby reducing the damage in case chine provided ith El 001ing' rrange- 15 of fire to a minimum. A still further object 61113 QCCOIdiHg to. the invention. of my invention is to provide a combined Fig. 2 is a radial section, to a larger scale cooling arrangement of the type referred to of a cooling element. which will as little as possible interfere with Fig. 3 is a section on the line of Fig. 2.

the active length of the stator body. Figs. 4 and 5 are sections, similar to Fig. 3, With the above objects in view I arrange, of modified iorms of cool1ng elements. between the individual groups of lamina- Flg. 6 1s a radial section of the cooled stator tions of the stator iron, liquid-cooling eleiron on the line 66 of Fig. 5. ments as well. as air ducts or passages so that Figs. 7 and 8 are views, similar to Figs. the warm air emerging from the rotor enters 35 of further modifications of the cooling such air aps and during its passage through elements. a them vcs up its heat which is removed, to- Fig. 9 is a longitudinal section according to oer with the heat arising in the stator, by line 99 of Fig. 100i a part of the stator iron, the liquid-cooling elements. It will be unshowing a further modification of simple ders ood that in addition to such air-cooling, construction and great efliciency. 3 liquid-coolig may be employed also for the Fig. 10 is a cross-section on line 1010 of rotor. Fig. 9.

Liquidcooling elements and air ducts may Fig. 11 is a section on the line 1111 of Fi be arranged in alternate spaces between the 10, showing a modified arrangement to be individual groups of laminations. In this seen also in the left hand side portion of case hmvcver the heat taken from the cooling Fig. 10. air must be transmitted through the full Fig. 12 is a diagrammatic cross-section of thickness of the group of laminations to be a machine, showing a preferred modification cooled so that not to exceed the admissible of the attachment for the cooling tubes. temperature fall the groups of laminations Figs. 13 and 14 are cross-sections to a larger 49 must he m.. e comparatively thin and the scale on the lines 1313 and 1414 respecco( inc; elem "s arranged comparatively tively of Fig. 12.

together; this can only be achieved at Fig. 15 is a longitudinal. section of the ma- 1!) expense of the length of the active iron chine provided with a cooling corresponding of the stator body. to diagrammatic Fig. 12 and An alternat ve consists in the arrangement Fig. 16 is a cross section on line 1515 of of the air ducts in the interior of thecooling Fig. 15. elements so that the warm cooling-air from Referring to Fig. 1 of the drawings the refthe rotor comes in direct contact with the erence letter a indicates the rotor of an eleccooling elements. Even this arrangement, trical machine and b the stator the iron body 59 however, has its disadvantages since firstly of which is composed of separate groups of laminations. Hollow cooling elements 0 which have the shape or flattened rings and in cross section are of the form, for example, illustrated in Fig. 2, are interposed between the separate groups of laminations. Said cooling elements communicate at two or more points with distributing and collecting conduits (Z, 0 connected to inlet and outlet pipes f and g respectively. Cooling water enters at f, is conveyed through the distributing passages (Z to the individual cooling elements 0,-

flows through these and through the collect ing passages e to the outlet 9, there either to be discharged orto be fed once more in continuous circulation through a cooler to the inflow pipe f; With closed circulation distilled water, for example condensation Water from a steam plant, may be used advantageously for the cooling. The cooling-elements illustrated in Figs. 2 and 8 are composed of two pressed sheet-metal laminations h, h which are welded together at the flange 7L3. At the inner circumference the laminations k may be furnished with extensions 7L, cut out to correspond with the teeth of the stator iron and welded'or solder d with the correspond ingly toothed, U-shaped ring insertion 7L2. The insertions 2' which are arranged concentrically, as illustrated in Fig. l, are provided to give stiffening against axial pressure. The relative positions of these insertions i may be determined by welded radial ribs j which are located in recesses (Fig. in the lateral walls h of the cooling element. In this way ribs are formed which on the one hand effect the con- 'duction of the heat from the stator iron to the cient cooling of the stator, such cooling or the rotor cooling air is attained as to make the quantity of air in the interior of the housing sufficient for the rotor cooling. The quantity oi circulating cooling air, out ofl from the outside air, is then so inconsiderable that on the occurrence of lire in the machine the air present is used up before any'great damage can occur.

Fig. 4 is asection, similar to Fig. 3, of a modified arrangement wherein the elements interposed between the groups 7),, 6 of laminations are provided with caston ribs whereby airducts 'Z are formed between the stator iron 6 to be cooled and the walls It of the cooling element. 1 I

Figs. 5 and '6 illustrate a construction in which the cooling elementsv are formed'from a plurality of fiat tubes 0 which have a crosssectional shape approximately that of a parallelogram. The ribs 70 are formed by recesses in the tubes.

In the examples illustrated in Figs. 2 to 3 the air ducts formed between the ribs 76 are located on one side of the cooling element while on the other side the cooling element is in direct contact with the stator iron over its entire extent. V

In all the modifications described it is possible with advantage to provide the ribs 70 on both sides of the cooling element. 1

In the arrangement illustrated in Fig. 7 the recesses or ribs 0 are located alternately on either side of thetubes 0 F 8 shows an alternative construction wherein cooling passages m for the air are carried through'the centre of the cooling ele ment 0. As is clear from the figure th1s arrangement is less suitable than those preceding since the thickness of the cooling element in the axial direction of the machine is increased due to the air passages located in the interior of the cooling element.

In the modification shown in Figs. 9 and 10, the cooling surface presented to the coolmg air is considerably increased. .The reference letters 6, 6 indicate two neighbouring groups of stator laminations between which the water cooled cooling elements 0 are located consisting, for, example, of a plurality of concentric annular tubes of flattened crosssection. The stator laminations Z), b adjacent t-he cooling elements 0 are furnished with .radial slots r separated by intermediate portions of lamination t. Said portions 25 abut against the cooling elements 0 and provioe for the heat-conduction between the rest of the stator iron and said cooling elements. The slots 7' are so long that they project at both ends beyond theinner and outer limits or edges 21 and 12 respectively, of the cooling element a. Openings 1 are thus formed for the entry of the air current flowing in the direction of the arrow through the machine. The warm air entering by the openings Q passes along the passages formed by the slots 7", is efiioiently cooled'therein and enters a gap w between the'two groups 6, b of laminations by the openings 8, leaving the stator through said gap; it then flows in acooled condition back to the parts of the machine to be cooled. The air passagestormed by the slots r are bounded on the one hand by the unslotted .laminations of the stator iron and on the other hand by the cooling elements 0. Since the groups of laminations Z; are in die rectheat-conductive, connection, through the intermediary of the thin connecting portions or ribs 5, with the cooling elements, groups of laminations are well cooled and the air to be cooled thus contacts with cold walls.

In the modification illustrated in Fig. 11 and the left hand side of Fig. 10, good heatconducting, metallic spacing ribs as are disposed radially between the stator laminations 6: bounding the air passages r adjacent the cooling element (2 and the remaining stator l1; itions 2;. Between hese ribs .1: r1. ill air i 3 are iornicd wh ch are bounded on all. 1 by well cooled walls. The ribs :0 may also be stann'icd up fri in the ne t lamiu ri adjacent the unslot" Kl liiilil. 'iUH 7) which ithen oi? exactly the same form as the first lamination Z) Round holes 2 and incisions which communicate with the inner and outer ends respectively oi the radial slots are stamped out from the lamination 5 located between the two lamination furnished with said radial slots. Consequently the air entering at Q flows oily in p; through tne gaps r, the oth r part passing through the holes 2 into the gaos "o Orr:

doubled.

lVhen the cooling elements comprise sea eral concentric tubes or psages, the lat may be connected at their ends to the cistributing and collecting cond in Si ch a manner that any tubes whien nave become leaky may be cut out individually.

Fig. 12 illustrates a very suitable arran ement for this purpose.

The individual cooling elements consist of tubes 0 which project from the active stator iron to be cooled. At their ends, 0 they have a circular cross-section l3) wherun in the part situated between the cups of leannations of the statn' th pressed flat (Fig. M) in substantially the manner illustrated in Fig. 6.

The ends 0 of the cooling tn in holes in the tops of the be; =iapcd tribuinn; and collecting com o UM. (Lie .2.

(Z and e comniiniicating with the inlet f and outlet g respectively. After the removr bottom covers and c of the distril in and collecting conduits respectively the niorths of the damaged cooling tubes ma be closed by means of any ipropnate stopping means.

In the zrrangen'ient illustrated in Fig. l the entry and outlet of the cool' g liquid occur at two diametrically oppo: to points on the stator. be modified by pa. s ng the water around stator, not through an an e oil 1 through. a larger arc and it occz around the entire circumference or as shown in Figs. 12 and 16, in n the entry ant outlet for the cooling liquid would be located, say, at the lowest point in the stator housing. Natural y the cooling elements may also consist o 3 shorter ments.

In order to reduce the air ca Jacity of the This ar'angement may however LAlQ housing provided with machine housing to a minimum, said housing is, as is clear from Figs. 1 and 12 and 16, provided with recesses 7) to receive the connecting, collecting and distribut'ng pi pes, the number of such r cesses depending upon the particular arrangement of thesi parts em ployed.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1.. An electrical machine comprising a rotor, a stator with an iron body composed of a plurality of groups of laminations, a pinrality of liquidcooling elements each interposed between two 01? said groups of la ninations and so formed to have thermally conductive contact therewith, distributing and collecting conduits in communication with the end of said liquid-cooling elements, a machine housing provided with radial projections forming recesses to accommodate the ends of said liquid-cooling elements as well as said distributing and collecting conduits, and said liquid-cooling elements shaped to form a plurality of substantially radial air ducts betwen said liquid-cooling elements and i aid groups of laininations to. r c ii'e the warm ir emerging from the rotor.

2. An electrical machine comprising a r tor, a s"ator with an iron body composed of plu 'ality oi? groups of laminations, a plu- "-cooling elements each intereffort I each of said concent o. ges to enabl a L 1 H q i; :1 mean LO 3e cu. on in i ii-nn sari. l' ontin and collect? ts and said uid-cooi elenieits 'orni a pinity of substaniall rat lucts disributed between said ig elements and said groug'is oi lamir: ions to receive the warm air emerging "roin the rotor.

23. Electrical mach .e comprising a. rotor 11 body composed oi a t lan'iinations. a plural lements ea eh i do a. stator with an iro plurz lily of grout it; of limiid-coolingz i p between two of said 'roups of laminations so formcc to h: ve thorn ally c contact therewitln and each cor several concentric pass collecting conduits in, (30121111! the ends of each of said concentric pa urges. he: s alto: no; access to the ends of each ot sa1 i concentric iges to nable them to be cut 0. ividnally troin said d tributinoj and cocccting cond a machine U it rad projections forming recesses to accon'nnodate the ends of said liquid-cooling elements as well as said CID distributing and collecting conduits and said liquid-cooling elements shaped to form a plurality of substantially radial air ducts distributed between said liquid cooling elements and said groups of laminations to receive the warm air emerging from the rotor.

In an electrical machine comprising a rotor and a stator with'an iron'body composed or a plurality of groups oi laminations, the combination with a plurality of liquid-cooling elements each so interposed between two of said groups of stator laminations and so formed as' to have thermally conductive contact, therewith, of a' plurality of substantially radial air ducts bounded on the one hand by said liquidrooling elements and on the other by said stator iron body and formed by radial slots cut in the stator laminations adjacent said'cooling elements so as to extend beyond both the inner and outer limits of the latter.

5. In an electrical machine comprising; rotor and a stator with an iron. body composed of a plurality of roups of laminations, the con'lbinations with a plurality of liquidcooling elements each so interposed between two of said groups of stator laminations and so formed .as to havethermally conductive contact therewith, of a plurality or. substantially radial air ducts located between said coolingelements and said groups of stator laminations so as to be bounded on the one hand by said coolingelements and on the other by said stator iron body and adapted to receive the warm air emerging from said rotor and conduct it in direct contact with. said liquid-cooling elements through said stator, thermally conductive spacing ribs being provided between such stator laminations as bound said air gaps and the remaining laminations'oi the group.

6. In an electrical machine comprising a rotor and a stator with an iron body composed of a plurality of groups of laminations, the combination with a' plurality of liquid cooling elements each so interposed between two of raid groups of stator laminations and so formed as to have thermally conductive contact therewith, of plurality of substantially radial air ducts located between said cooling elements and said groups of stator laminations and formed by radial slots cut in the stator laminations adjacent said cooling elements so as to extend beyond the inner and out-er l mits of thelatter, holes registering with the inner ends, and incisions partly registering with the outer of said radial slots being cut in the next laminations, and such radial slots alternating with such holes and incisions in subsequent lai .inations,

7. An electrical machine comprising a retor, a stator, with an iron body composed "of a plurality of groups of laminations, plurality of liquid-cooling; elements each so in terpose'd between two of said groups of laminations and so formed as to have thermally conductive contact therewith, and each consisting of several concentric passages of a flattened cross-section in the portion located between the stator laminations and of circular cross-section in the end portions projectfrom the laminations, distributing and collecting conduits in communication with the circular ends of each of said concentric passages, means affording access to said circular ends of each of said concentric passages to enable the latter to be individually cut oil tromsaid distributing and collecting conduits, and a plurality of substantially radial air ducts distributed between said groups of laminations to receive the warm air emerging from the rotor.

8. A electrical machine comprising a rotor, stator with an iron body composed of a plurality of groups of laminations, a plu rality of liquid cooling elements each so interposed between two of said groups of laminations and so formed as to'have thermally conductive contact therewith, and each consisting of several concentric passages, boxshaped distributing and collecting conduits having an inner wall provided with perforationsto receive the ends of each of said concentric passages, and an outer removable cover opposite to said innerwall, and said liquid-cooling elements shaped to form a plurality of substantially radial air ducts distributed between said groups of laminations to receive the warm air emerging from the rotor. V

9. An electrical machine comprising, in combination, a rotor, a stator with an" iron body composed of a plurality of group'sof laminations, means providing a cooler for the stator iron and air from the rotor, comprising'liquid conducting conduits between the groups of stator laminations in thermal con ducting contact therewith, said conduits iaped to form air passages between said conduits and the walls of said groups of laminations for the air from the rotor, whereby liquid flowing, through said conduits is ef fective to cool said laminations and said air.

10. An electrical machine comprising, in combination, a rotor, a stator with an iron body composed of a plurality of groups of laminations, meansproviding a cooler for the stator iron and air from. the rotor, comprising liquid conducting. conduits between the groups of stator Llaminations in thermal conducting contact therewith said conduits shaped to form radial air passages at both lat eral sides thereof between. said conduits and the walls of said groups of laminations for the air from the rotor.

11. An electrical machinecomprising, in combination, a rotor, a stator with. an 'iron body composed of a pluralityof groups of laminations, means providing a cooler to} the stator iron andfair from the rotor, compris 

